CPseudonym
Moderator Emeritus
This thread cracks me up.
I had no Earthly idea figuring out the air draft of a boat could be so complicated. ?
? You must be new around here.
This thread cracks me up.
I had no Earthly idea figuring out the air draft of a boat could be so complicated. ?
This thread cracks me up.
I had no Earthly idea figuring out the air draft of a boat could be so complicated. ?
Years ago I saw one of these, cheap at $30, so I bought it: https://www.amazon.com/Davis-Mark-3-Sextant-Marine/dp/B0014476FI
Ulyssis suggested using a grade 9 math student or an app for your phone. Using a sextant is so much more fun.
Find some place where you can see your anchor light, and also get an accurate measurement from your eye level to the water surface. measure the angle with the sextant. Measure the distance to the centerline of your boat. Do the math. Back before the "new math" this would be a problem for grade 10, but your I-phone should be able to help you.
Pythagoras solved this issue many years ago and provided it to Euclid.
Measure with tape or string from your top most point straight out to the water preferably to abreast the beam, without touching anything else on the boat. Don't try measuring straight down but out and away from the boat. Then measure from the spot you are touching the water to the boats hull. Add 1/2 of the hulls width to the second measurement. You have established a right angle in which you now know the hypotenuse and one side. Do the math to solve for air draft.
So how do you mark the spot on the water and how do you measure from there to the boat?
I think the OP has the most practical plan.
This thread cracks me up.
I had no Earthly idea figuring out the air draft of a boat could be so complicated. ��
So how do you mark the spot on the water and how do you measure from there to the boat?
I think the OP has the most practical plan.
Use the old Boy Scout / logger method to est ht of a tree to fell.
Stand away from the object...abeam og the boat. ..
With a stick or pencil in hand and arm extended place tip on highest pt and place a finger at bottom...waterline.
Now rotate extended arm 90* and place finger at stern of boat..note where tip lands...have a helper stand there if necessary
Now measure distance from stern to helper or noted location...
Easy peezey air draft...don't even have to climb aboard or get to highest pt.
You bet...and out there in the PNW I'll bet you could find a logger to assist! [emoji1]I like this idea. I never would have thought of it yet it is simple, and if done carefully, would be very accurate.
Measure from the building's ceiling down. When my boat was in the building for the refit,
Ted
For most of our boats, there's no direct path from the highest point straight down to the water so we cannot use use a tape measure.
What is your suggestion?
I'm more worried about the markings of bridges being accurate. Plus the latest quote from a bridgetender "I am FORBIDDEN to divulge weither or not there is additional clearance at the center".
No problem, open the bridge!
Most bridges in my area (SE Florida) have a sign stating that the center is 5 feet higher than the number showing on the marker. This is due to the curvature of the span.